Sailing small water craft and windsurfing are popular pastimes. Important criteria to the newcomer of these sports are the learning and understanding the intricacies of wind, sail and mobility. One method to aid in this learning process is utilization of a remote controlled, wind-propelled vehicle that simulates the physics of windsurfing where one can safely learn how to control and react to diverse wind conditions. In order to more fully simulate the sailing and windsurfing experience the vehicle must be designed to accurately mimic conditions and maneuvers associated with these sports. These include a light weight vehicle with sail and center of gravity forward of the stern or rear axle for maximum wind propulsion, simulation of the physics of lift, and the ability of the vehicle to make tight turns while avoiding the hazard of rollover or capsizing.
Alternatively, the remote controlled, wind-propelled vehicle can be used for entertainment and competition, including the enjoyment of maneuvering and playing with the vehicle on a flat surface and racing the remote controlled vehicles and/or display skills involved in this type of activity. Such remote-controlled vehicles can be a low cost form of learning and entertainment because the power used to propel the vehicle is provided by the wind, thereby the only non-wind power requirement is for the steering of the vehicle.
A wind propelled sail toy vehicle is described in U.S. Pat. No 4,886,478. This remote controlled land vehicle has a rod-like elongated frame with a mast attachment for a sail and a raised forward portion engaged to a front wheel assembly, plus an elongated axle with wheels at each end. When the sail of the sail toy vehicle is in position, the center of gravity is over the rear axle rather than forward of this location and does not attain maximum wind propulsion. In addition, the lengthy axle assembly of this vehicle is necessary to prevent rollover during sharp turns, inhibiting maneuverability and a more accurate simulation of windsurfing. This vehicle also lacks the option of a frame support reducing the strength of the overall structure.
Rigid Wing Sails
Rigid wing sails are well known and are utilized for a variety of wind powered craft, including sail boats, wind surfers and hang gliders. A rigid wing sail differs from a soft flexible sail in that the former has a solid construction so that the shape of the rigid wing sail remains more or less fixed throughout the entire sailing regime. Contrasting to this arrangement is the soft flexible sail which is held in an airfoil shape by battens but otherwise free to shift from side to side and change its shape based on the needs of the sailor.
Aerodynamic properties of conventional thin, soft flexible sails are poor compared to the properties of wing sails. Speed sailors recognize this fact to the extent that basically all records in speed sailing on water, land and ice have been achieved with wing sails, usually of rigid type. However, rigid wing sails have some significant disadvantages. They are heavy and expensive. They are also impractical. For example, rigid wing sails are totally unsuited for the vast majority of sailboats, which require that the sails be readily removable and stowable.
What is needed is a better wind propelled vehicle.